The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRemoval
Discharge refrigerant from
refrigeration system (see page ac-172)
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove ...
Battery current sensor
On-vehicle inspection
Check battery current sensor assembly
Measure the resistance of the sensor.
Standard resistance
If the result is not as specified, replace the sensor
assembly.
Measure the resistance of the sensor.
Standard resistance
If the result is not as specified, ...
Opening and closing procedures
The power windows can be opened and closed using the switches.
Operating the switch moves the windows as follows:
Closing
One-touch closing (driver’s window
only) (if equipped)*
Opening
One-touch opening (driver’s
window only)*
*: To stop the window partway, operate
the ...